1. Field of the Invention
This invention relates generally to perpendicular magnetic recording systems, and more particularly to perpendicular magnetic recording write heads for use in magnetic recording disk drives.
2. Description of the Related Art
In a perpendicular magnetic recording system like a magnetic recording hard disk drive, the recorded bits are stored in a perpendicular or out-of-plane orientation in the recording layer. The recording or write head in perpendicular magnetic recording disk drives is a set of patterned thin films on the trailing surface of an air-bearing slider that has an air-bearing surface (ABS) that faces the recording layer on the disk. The write head includes a main pole with a tip at the ABS, a magnetic yoke connected to the main pole, an electrically conductive write coil with multiple turns through the yoke, and one or more return poles for return of magnetic flux from the recording layer.
As the data rate increases in magnetic recording systems, it is desirable for the write head to have a short yoke, i.e., a yoke with a small height as measured from the ABS, in order to minimize the time for the magnetic flux to travel to the pole tip. However, the amount of reduction in the height of the yoke is limited by the requirement for a certain number and size of coil turns in the yoke.
The write current through the coil also generates heat, which causes undesirable pole tip protrusion. One approach to address this problem is to add separate thermally conductive heat sink layers near the coil to dissipate the heat. However, this increases the complexity of the write head fabrication process.
What is needed is a write head that enables a reduction in yoke height and dissipates heat to reduce pole tip protrusion.